[time-nuts] Some More questions

Poul-Henning Kamp phk at phk.freebsd.dk
Thu Jan 19 14:50:41 EST 2006

In message <ad9f78230601191100h7f822e2fp21a9f857b936185e at mail.gmail.com>, Matt Ettus writes:
>On 1/19/06, Hal Murray <hmurray at suespammers.org> wrote:
>> > Then, I am not sure all GPS receivers actually use their internal
>> > crystal oscillator in a PLL as the timebase. I have read that some
>> > work  by removing or adding pulses in a discrete fashion rather than
>> > phase  locking, and this offers significant jitter, making the 1 PPS
>> > only  useable to phase lock a reference oscillator with a very long
>> > integration period to eliminate the jitter.
>To my knowledge, nobody tunes the frequency of the oscillator in their
>GPS receiver.

High end GPS receivers can take an external clock signal from your
10MHz house standard.

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.

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